Since version 4.78 Discovery fully supports singleplayer. Open Singleplayer is not included, but it is available as a stand-alone modification.
I have tried the Open SP mod. I see no story line here. Is this a new single player game that has scripted missions like the origional single player game or just a place to play if you don't always have internet capabilities?
BabyDoc: Large Train
DragonKnight: Liberty Assault Frigate
Shadowen: Albatross Frigate
[MiD]The_Enforcer[Ace]: Rheinland bomber
[DJC]The_Kraken: Heugenot Cruiser